1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180

extern crate alloc;

use alloc::boxed::Box;
use alloc::vec;
use alloc::vec::Vec;
use core::convert::TryInto;

use crate::filter::{Filter, FilterError, INCREMENT_STATE_BY_CONST_FILTER_CODE};
use crate::serializer::{ConfigSerializerError, Serialize, TryDeserialize};
use crate::state_manager::StateManager;
use crate::{ExtractorValue, Value};

#[repr(C)]
#[derive(Debug, PartialEq)]
pub struct IncrementStateByConstFilter {
    state_index: u32,
    increment_value: Value,
}

impl IncrementStateByConstFilter {
    pub fn new(state_index: u32, increment_value: Value) -> Self {
        Self {
            state_index,
            increment_value,
        }
    }
}

impl Filter for IncrementStateByConstFilter {
    fn filter(
        &mut self,
        _value: &ExtractorValue,
        state_manager: &mut StateManager,
    ) -> Result<bool, FilterError> {
        let new_value = match (
            state_manager.get_value(self.state_index),
            &self.increment_value,
        ) {
            (Some(Value::U8(current_state)), Value::U8(increment_value)) => {
                Value::U8(current_state.wrapping_add(*increment_value))
            }
            (Some(Value::U16(current_state)), Value::U16(increment_value)) => {
                Value::U16(current_state.wrapping_add(*increment_value))
            }
            (Some(Value::U32(current_state)), Value::U32(increment_value)) => {
                Value::U32(current_state.wrapping_add(*increment_value))
            }
            _ => return Err(FilterError::WrongStateType),
        };

        state_manager.set_value(self.state_index, new_value);

        Ok(true)
    }

    fn get_code(&self) -> u16 {
        INCREMENT_STATE_BY_CONST_FILTER_CODE
    }
}

impl Serialize for IncrementStateByConstFilter {
    fn serialize(&self) -> Vec<u8> {
        let state_index_bytes = self.state_index.to_be_bytes();

        let mut data = vec![
            state_index_bytes[0],
            state_index_bytes[1],
            state_index_bytes[2],
            state_index_bytes[3],
        ];

        let mut increment_value_bytes = self.increment_value.serialize();

        data.append(&mut increment_value_bytes);

        return data;
    }
}

impl TryDeserialize for IncrementStateByConstFilter {
    fn try_deserialize(data: &[u8]) -> Result<Box<Self>, ConfigSerializerError> {
        if data.len() < 6 {
            return Err(ConfigSerializerError::WrongSize);
        }

        let state_index = u32::from_be_bytes(data[0..=3].try_into().unwrap());
        let increment_value = *Value::try_deserialize(&data[4..])?;

        Ok(Box::new(Self {
            state_index,
            increment_value,
        }))
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn initial_zero_increment_by_five_test() {
        let mut state_manager = StateManager::new();
        state_manager.set_value(0, Value::U32(0x0000_0000));

        let mut filter = IncrementStateByConstFilter::new(0, Value::U32(0x0000_0005));

        assert_eq!(
            filter.filter(&ExtractorValue::None, &mut state_manager),
            Ok(true),
        );
        assert_eq!(
            *state_manager.get_value(0).unwrap(),
            Value::U32(0x0000_0005),
        );
    }

    #[test]
    fn initial_max_increment_by_one_test() {
        let mut state_manager = StateManager::new();
        state_manager.set_value(0, Value::U32(0xffff_ffff));

        let mut filter = IncrementStateByConstFilter::new(0, Value::U32(0x0000_0001));

        assert_eq!(
            filter.filter(&ExtractorValue::None, &mut state_manager),
            Ok(true),
        );
        assert_eq!(
            *state_manager.get_value(0).unwrap(),
            Value::U32(0x0000_0000),
        );
    }

    #[test]
    fn wrong_state_type_test() {
        let mut state_manager = StateManager::new();
        state_manager.set_value(0, Value::U8(0x00));

        let mut filter = IncrementStateByConstFilter::new(0, Value::U32(0x0000_0001));

        assert_eq!(
            filter.filter(&ExtractorValue::None, &mut state_manager),
            Err(FilterError::WrongStateType)
        );
    }

    #[test]
    fn serialize_test() {
        let filter = IncrementStateByConstFilter::new(0xabab_abab, Value::U32(0xffff_ffff));

        let expected_data = vec![0xab, 0xab, 0xab, 0xab, 0x02, 0xff, 0xff, 0xff, 0xff];

        assert_eq!(filter.serialize(), expected_data);
    }

    #[test]
    fn deserialize_test() {
        let data = vec![0xab, 0xab, 0xab, 0xab, 0x02, 0xff, 0xff, 0xff, 0xff];

        let filter = Box::new(IncrementStateByConstFilter::new(
            0xabab_abab,
            Value::U32(0xffff_ffff),
        ));

        assert_eq!(
            IncrementStateByConstFilter::try_deserialize(&data),
            Ok(filter)
        );
    }

    #[test]
    fn deserialize_wrong_size_test() {
        let data = vec![0xab, 0xab, 0xab, 0xab, 0x02, 0xff, 0xff, 0xff];

        assert_eq!(
            IncrementStateByConstFilter::try_deserialize(&data),
            Err(ConfigSerializerError::WrongSize)
        );
    }
}